The code was basically leaking memory everywhere, and apparently on
purpose (according to a top comment). Even on short-lived process, not
properly managing memory is not a good habit, especially if we plan to
maintain a program for the long run.
So here are some fixes. I'm sure I must have missed some places (code
was a mess), and hopefully I broke nothing. But that's good for now. At
least it is somewhat sane code now.

(cherry picked from commit f3de5cd3)